Hi, should I go 3.73 or 4.10 from my stock 3.27 gear?

[haktmal]

Hi, should I go 3.73 or 4.10 from my stock 3.27 gear?

I have a 1998 Sport 2wd 4.0 OHV. I want to swap the stock gear and also get a LSD or a locker (aussie perhaps) and here are my options:

(1) Go 3.73 and get 31" tires without having to lift the Sport.

(2) Go 4.10 and get 32" tires and I have to lift the Sport.

Lifting the Sport is another whole mess with money.

This is my daily vehicle and I do a lot of highway driving. I tow the boat out about once or twice a month.

Is there a way I can run 4.10 and 32" tires w/o having to do some expensive lifting work? Or is there a way I can just lift the Sport 1" or 2" higher w/o having to buy the entire lift kit? This is by all means, lifting the front and the rear.

Please give me your opinions.

And thank you!

Nathan

 

[becker69]

Nathan; I have 4.10's with the SOHC motor and 32's and it's fine. If you are considering a L/S or locker I would definately go with the 4.10's so you have some leverage with tire choices now and later (especially if you are going to spend $$ at the same time!!). I do have more wheel-well space for the 32's than you have on the sport.
Do some looking and searches on the TT for the front and the Shackles in the rear; should give you 1.5" or so and then see what kind of tires you can fit... I will guess you could easily fit 31's and may have to trim some for the 32's... But others here know better than I. You could also look into lift spindles for the front, AAL's, etc.

The 4.10's will also make towing a bit more easy!

 

[SteveVB]

I wopuld get the 4.10s and you can run either the 31s or the 32s.

I wouldnt even consider the 3.73s

I run4.10s with 31s and it is fine around town and on the highway.

 

[88vert]

I have 3.73's with my 32's and it has great pickup and gas mileage

 

[haktmal]

StevevB,
But isn't the exact tire size and gear match is
3.73 for 31s
and
4.10 for 32s ?

and if you're riding 4.10 with 31s (without lift), you will be loosing mileage more because the speedometer doesn't calculate correctly?

My main concern is that say I'm riding 4.10 gear with 31s tires. And my speedometer will read 75mph while I'm actually only going 65mph. This will add 10 more miles to my speedometer in every hour driving.

 

[SteveVB]

Exact tire size to gears???

Nope, there is no exact match gears to tire sizes. Matter of fact there is no such thing as an exact tire size- tires labeled 31" can be anywhere from 29 to 32 inches tall depending on manufacturer, the width of the wheel they are mounted on, inflation pressures, and even wear.
The same truck from the factory could come with 3.08,3.27, 3.55,3.73s much much more than tire size goes into gearing. Engine, use, trans, tires, etc.

There are some general guidelines that experience on this site tells us work well for power and I would say 31s and under 4.10s, 32-35s 4.56s, 36 and up 5.13s. All im saying is that 4.10s would be my choice from what youve written. IF you had 3.73s I would say dont change them, but you dont, and if you are going through the trouble and expense to swap gears, combined with the comments you have wtritten about wanting more off the line oomph, and more passing power I would say install the 4.10s.
I dont think Ive ever seen anyone complain about gears that are too low, most swap in gears and complain they are too high.

If you change the gears in the axle you can change the gears in the speedo cable to compensate - so it really doesnt matter. You shouldnt be concerned about the speedo- its a 20 dollar part and a 20 minute fiix to get it to read correctly. That said Ive been driving around for a year without changing the gears its not that big of a deal to me. The only thing the speedo does to your mileage is make it harder to compute- the speedo has no effect on what fuel mileage you get, just the calculation of it.

Focus on what you want the truck to do and what the gears are going to get you- added acceleration, better towing, better fuel mileage etc. You really should think about your whole truck and how you are going to use it. Engine, trans, use , tires, wheels, etc to see what gears you need, tire size is only one part.


Good Luck